This invention relates to a device useful with an existing bedframe, for raising and lowering a portion of a mattress.
Devices for raising and lowering a portion of a bed mattress are well known. In the most common type of such device, the adjustment mechanism is part of the bed structure. As is easily understood, a device that can be added to and removed from an existing bedframe is more adaptable and can be provided at a lower cost. For purposes of this discussion of this invention, by "bedframe" is meant bed rails, and supporting legs therefor.
Devices for adjusting the position of a portion of a bed mattress are exemplified by U.S. Pat. Nos. 3,191,195 to Schlackman et al, 3,750,200 to Hirmann, 3,781,928 to Swallert, and 4,435,862 to King et al.
The Hirmann patent is directed to a device for hydraulically setting the position of a bed. The device includes an inflatable hose connected to a source of low-pressure water. The Schlackman et al patent pertains to a hospital-type bed that includes, as part of the bed structure, hydraulic pistons and cylinders for raising and lowering portions of the bed rails.
The King et al patent relates to a control arrangement for a motor driven adjustable bed. The microprocessor control provides for bed adjustment in response to command signals indicating selected bed positions. The Swallert patent is directed to a device useful with an existing bedframe. The device includes a pneumatically inflatable pad disposed between pivotally joined, U-shaped, upper and lower frames.
However, there continues to be a need for an improved device useful with an existing bedframe, for raising and lowering a portion of a mattress. For instance, the inflatable member of the Swallert patent is vulnerable to puncture. Beneficially, such an improved device would be capable of improved automatic operation. Advantageously, such an improved device could adjust the mattress of a full size bed, of a queen size bed, or even a king size bed.